It is typical for an operating gas compressor to develop a resonant frequency in its structure. This resonant frequency is determined by a great number of factors, including the design of the gas compressor, stiffness of the gas compressor structure, structural materials, operating speed and so forth. It has also been found that there are frequencies and ranges of frequencies which are perceived as more and less loud by the human ear. Therefore, it is desirable to control the resonant frequency of a gas compressor, so as to limit the perceived noise of the gas compressor. Typically this is achieved by selection of structural materials and designs which provide suitable structural strength and the desired gas compressor performance while incidentally lowering the perceived noise. The perceived noise is then typically further reduced by the addition of mufflers and sound deadening materials to the gas compressor. However, in order to obtain a cost effective design of the gas compressor, it is not feasible to bring this perceived noise as low as desirable.
In consideration of the foregoing, it is an object of this invention to provide an apparatus and a method of altering the structural resonant frequency of a gas compressor in a cost effective manner.
It is a further object to provide for altering the structural resonant frequency of a gas compressor to a determined resonant frequency to produce a lowered perceived noise of the gas compressor.
Another object is to provide for altering the structural resonant frequency of the gas compressor without requiring structure of substantially increased stiffness and weight.
These and other objects of the invention will be apparent from the attached drawings and the description of the preferred embodiment that follows hereinbelow.